Switches of the trigger type have been known heretofore. However, these switches have generally included a direct connection between the operating member and the movable contact causing actuation of the contacts toward closing immediately upon movement of the trigger. This subjects the switch to accidental closure when a portable tool is being handled.
Switches of the preloading, free play or lost motion type have also been known. Such preloading has been used in switches of the toggle lever or push-button type or the like for snap-action purposes. Thus, initial movement of the operating member causes compression or preloading of a spring while the movable contact is held by a spring-biased detent and, when the preloading overcomes the restraining action of detent, the switch snaps to its operating position. Free play has been used to impart an impact force or so-called "hammer blow" to aid in opening partially welded contacts, a very short free play being generally sufficient therefor. Lost motion has been used for overtravel purposes and the like when the thing that operates the switch must be allowed to keep moving after the switch has been operated thereby to avoid damaging the switch.
While these prior switches have been useful for their intended purposes, this invention has a different purpose, that is, to prevent accidental closure of the switch.